Indicating system



Aug. ,1 B. b. WILLIS 2,355,352..

INDICATING SYSTEM Filed April 30, 1942 s ShetS -Sheet 1 SENDING STATIONCONTROL MECHANISM lo: 102 I03 I04 :05 v

' CHECKING INDICATOR PANEL led l4 mmcmoak? 2 RESTORING a KEY I40 W PEN .RECORDR INDICATOR "E i PASS KEY I CALLING DEVICE I u4 +fi |24 133 I64|25L I345. I462. LAMP 1 fl;

GAELL BACK I65 LAM$G1 F 1 INVENTOR.

BERNARD D. WlLLlS, DECEASED BY WM WALTER OWEN, EXEGUTOR INDICATING'SYSTEM Filed April 30; 1942 3 Sheets-Sheet 2 CONTROL MECHANISM DIGITSEQUENCE 8! INDICATOR SELECTING SWITCH 250,

men SEQUENCE swncu 20o REG. 00m. CIR

p TEST REPEATING- R220 223 INVENTOR.

BERNARD D. WILLIS, DECEASED BY WM. WALTER OWEN, EXEgUTOR I av 9%, W

ATTORNEYS Aug. 8, 1944.

CONTROL MECHANISM B. D. WILLIS INDICATING SYSTEM Filed'April 30, .1942 3Sheets-Sheet 3 RECEIVING STATION l (i (J I 11121211308U32 U235 4 m [7- Eri l INDICATOR GROUP 300 INDICATOR GROUP 350 INDICATOR com.

cmcun 31 0 7 I F 34! /342 INDICATOR RESTORING 5 KEY 340 am PULSELGENERATOR 'CALL BACK n 5 INVENTOR. BERNARD D. WILLIS, DECEASED BY WM.WALTER 0 EN, EXECUTOR W-ZmkxrM BY e ATTORNFYQ Patented Aug. 8, 1944INDICATING SYSTEM Bernard D. Willis, deceased, late of Oak Park, 111.,

by Wm. Walter Owen, executor, Elgin, 111., assignor to AutomaticElectric Laboratories, Inc., a corporation of Delaware Application April30, 1942, Serial No. 441,113

3 Claims.

The present invention relates to indicating systems and, moreparticularly, to, improvements in systems for transmitting informationreceived at one point to a remote point for visual display thereat.

It is an object of the present invention to provide a system of thecharacter described which is simple in arrangement, includes facilitiesfor posting several different items of information, utilizes a minimumof equipment, and is positive and reliable in operation. 1

It is another object of the invention to pro vide in a system of thecharacter described, a single automatically controlled switch which maybe of any desired type and is controlled to operate as a digitsequenceswitch for directing the impulses of successive digits to differentindicators and also to select'an idle group of indicators from aplurality of groups'of indicators associated therewith.

The improved indicating system, as described with particularity below,is of particular utility in transmitting information to the flightobservation point of an airplane dispatching or observing organization.A large map may be provided at this point for indicating the location ofplanes flying within agiven area. Observers variously located throughoutthis area may, by using telephone or other communication facilities,transmit to a central operator descriptions of planes observed withinthe area and the directions of flight of the observed planes. Theoperator, upon receiving this information, may utilize the improvedsystem as herein disclosed to transmit the received information to theflight observation point.

The invention, both as to its organization and method of operation,together with further objects and advantages thereof, will best beunderstood by reference to the specification taken in connection withthe accompanying drawings in which Figs. 1, 2 and 3, when placed side byside in the order named, illustrate a system characterized by thefeatures of the present invention.

Referring now more particularly to the drawings, the systemthereillustrated comprises a display board which is provided with a pluralityof groups of indicators 300,350, etc. This display board is provided ata receiving station or observation point in the view of an attendantwho, upon receiving the information set up in any group of indicators,may record the received information upon a map, or chart, and. thenrelease the particular indicator group displaying the-information.Fiveindicators are pro vided in each of the several indicator groups.For example, the indicator group 300 comprises the five indicators 30],302, 3%, 304 and 385 which may respectively be operated by the receivedimpulses of the ten thousands, thousands, hundreds, tens and unitsdigits of a five digit code number utilized to set these indicators sothat theydisplay a desired indication. Each of these indicators is ofthe Well-known electro-mechanical type and is provided with a displayboard drum which may be rotated from a normal or blank position to anyone of ten cit-normal positions wherein the numerals 1 to 9 and 0 arerespectively displayed thereby. The indicating drum of each indicator ismounted on a drive shaft to which rotary movement is imparted in onedirection only by a pulse-controlled operating magnet and an associatedratchet and pawl or' Geneva gear mechanism. The drive shaft of eachregister also carries a cam which is arranged to control an associatedset of commutating contacts in the manner-more fully explainedhereinafter. If desired, the various indicators may be of theconstruction disclosed in Fig. 22 of Patent No. 2,234,684, granted March11, 1941, Martin L. Nelson and Harold C. Robinson.

Each group'of indicators has associated therewith an indicator controlcircuit which is utilized primarily to effect the release of theindicators in the associated group. For example, the indicator group 309has associated therewith a control circuit 310' which is illustrated ascomprising a connect relay R310, a start restoring relay R 38U,=and anoff-normal relay R390. Thesejthree relays are arranged to be controlledby an indicator restoringkey 346 which is also individual to theindicator group 35!!) and is provided at the receiving station. Itwillbe under-stood that similar control circuits and restoring keysindividual to the other indicator groups provided at the receivingstation are also included in the system. A call back key 365 islalsoprovided at the receiving station for en- .abling the attendant at thisstation to signal the operator at the distant sending station thatverification of a received item of information is required. p Y

The selective control of the indicators in the variousgroups is effectedfrom a remote point at which the information to be posted on the dis-.play boardis received. This remote point is illustrated as. comprisinga sending station at which is. provided the equipmentrshown to the leftof the vertical dash-line appearing in 1 ceiving station, a pen recorderI'I-I may also be provided at the sending station. 'Ihe checkingindicator panel I80 includes five electro-mechani cal indicators IIII,I02, I03, I04 andI'05 which are identical in construction andarrangement with those provided on the display board located at thereceiving station. It is provided for the purpose of permitting theoperator at the sending station to verify any given piece of informationtransmitted to the receiving station by observing the transmitted codenumber designating the item of information as this code number is set upin the checking panel;

As indicated above; the transmission of information from the sendingstation to the receiving station is effected by using definitely codedsets of impulses in digit form to control the indicators of a selectedgroup asprovided on the display board at the receiving station. Theautomatic switching equipment illustrated in Figs. 1 and 2 of thedrawings is arranged to be controlled by the calling device I60 toselect the different groups of indicators which are to receive thecodenumbers designating the different items of information, and to directthe, coded digits ofany particular code number to the appropriateindicators of the selected group.. This equipment comprises a digitsequence and indicator selecting switch 250 of the well-knownrotarytype, and a groupof control relays. More specifically considered, therotary switch 250 comprises four sets of contacts of twenty-five pointseach, wipers ZEI, 25I, 253 and 254 individually associated with the fourcontact sets, and, an operating magnet 255 which, in combination. withan associated ratchet and pawl mechanism, is arranged to drive theenumerated Wipers over the contacts of their associated contact sets. Inbrief, the relay. equipment includes a fast-acting pulsing relay RI II],three slow-to-release digit relays RIZI], RI3IJ and RI45, a pulserepeating relay RZllll, a test relay R220, and a stepping relay R230.The enumerated relays are also arranged to control the indicators .Ofthe checking panel I during the transmission of the digits of each codenumber. Inorder to direct the different digitsof a transmitted codenumber successively to the different indicators of the checking panelI60, a digit sequence switch 200 is provided. This switch is of thewell-known minor type, comprising, two sets of contacts of, elevenpoints each, Wipers 20I and 202 individual to the two contact sets, anoperatingmagnet 204 for driving the two wipers over the contacts oftheir associated contact sets, and a release magnet 203 which,

storing relays RIIll and RIBO are provided.

These two relays, like the release magnet 2 03 of the sequence switch200, are arranged to be controlled by the indicator restoring key. I40.For

the purpose of restoring to normal the indicators provided in thechecking panel I00 and on the display board located at the receivingstation, a pulse generator 3I I common to all of the indicators isprovided. This generator, which is only schematically shown, may be ofany desired commercial structure although preferably is of themotor-driven commutator type;

Current for energizing the indicator operating magnets, the controlrelays, the signal lamps, and the operating magnets of the rotary andminor switches, is supplied from a common direct current source, thepositive terminal of which is connected to a common bus conductor and toground. The negative terminal of the source is connected to a commonnegative bus conductor which terminates the various relay, magnet andlamp terminals identified in the drawings by the negative polarity sign.For convenience in describing the circuits involved, this source ofcurrent, which may conventionally comprise a storage battery floatedacross the terminals of a charging rectifier, has not been shown.

. In considering the operation of the system, it may be assumed that theoperator at the sending station receives an item of information which isto be transmitted to the receiving station at a time when all of theequipment provided in the system is at normal. It may be assumed furtherthat the wipers of the digit sequence and indicator selecting switch25!) occupy the positions i1- lustrated in the drawings. In such case, acircuit is completed through the wiper 254 and the contacts 224 and I35for energizing the go signal lamp I64. Theillumination of this lampserves to advise the operator at the sending station that the automaticswitching equipment is at normal and that one of the groups ofindicators of the display board located at the receiving station hasbeen selected to receive the digits of the code number designating theparticular item of information to be transmitted. More specifically,with the wipers of the switch 250 engaging their respective associatedfirst contacts, the illustrated indicators of the group 300 arepreselected to receive the digits of the code number. For explanatorypurposes, it may be assumed that the code number assigned to theparticular received item of information is the number In order to postthe code number identifying the particular item'of received informationon the display board at the receiving station, the operator at thesending station repeatedly actuates the calling device I69 to dial thedifferent digits of this number. When the dial of this device is firstmoved off normal, the off-normal springs. I62 and I 63 are closed tocomplete a circuit through the pulsing contacts IBI for'ene'rgizing thetwo windings of the pulsing relay RLI I0 in series. In operating, therelay RI I0 closes its contacts II3 to complete an obvious circuitlfo'renergizing the slow-to-release' digit reIay RQIZD. At its contacts II2,the relay RI Ill opens a point in the operating circuit for the digitrelay RI30. At its contacts In and ml, the rela aria pie, pares acircuit for energizing thepulserepeating relay Rzillinseries with theoperating-magnet 3660f the indicator Bill -in the selecteddhdicatorgroup 339. The digit-relay RI 20, upon operating, closes its contactsI23 to prepare the-operating circuit for the digit relay RUB.- Atitscontacts .IZI, the relayRI2il opens a, point-inthecircuit forenergizingthe operating -rnagnet zlltl of the d it equ nc switch .20."-ji cont in I?! the relay RI20 opens a point in the circuit forenergizing the operating magnet 255 of the rotary switch 250. At itscontacts l24, the relay RI29 further prepares the above-mentionedcircuit for energizing the pulse repeating relay R2 I in series with theoperating magnet 306 of the indicator 30I. At its contacts I25, therelay RI20 opens a point in the operating circuit for the test relayR220. During the dial return movement of the calling device I60, thepulsing contacts I-6I are opened and closed four times to transmit fourimpulses to the pulsing relay RI III. This relay, in releasing at thebeginning of the open-circuit period of the first impulse, opens itscontacts I I3 to interrupt the operating circuit for the digit relayRI20, and closes its contactsl I2 to complete the prepared operatingcircuit for the digit relay RI30. At its contacts III and II i,'therelay RI it opens the prepared circuit for energizing the pulserepeating relay R2 I 0 in series with the operating magnet 306 of theindicator 30 I. The digit relay RI30, upon operating, closes itscontacts I3I to prepare the circuit for energizing the operating magnet234. At its contacts I32, the relay Rl30 similarly prepares a circuitfor energizing the operating magnet 255. At its contacts I33, the relayR530 further prepares the circuit for energizing the pulse repeatingrelay R2 I 0 in series with the operating magnet 306 oi the indicator30i. At its contacts I34, the relay RI30 opens a point in the operatingcircuit for the test relay R220. At its contacts I35, the relay RI30opens the circuit for energizing the go signal lamp I60. Whendeenergized, this lamp indicates that the associated automatic switchingequipment is busy. At its contacts I36, the relay RI30 completes anobvious circuit for energizingiherelay RME. In operating, the relay RMEopens its contacts I46 further to interrupt the operating circuit forthe relay R220. 7

When the pulsing relay RI I0 reoperates at the end of the open-circuitperiod of the first impulse, it closes its contacts M3 to recornpletethe oper-.

ating circuit for the digit relay RI20, and opens its contacts I I2 tointerrupt the operating circuit for the digit relay RI30. At itscontacts I I I and I I0, the relay RI l0 completes the prepared circuitfor energizing the pulse repeating relay R2I0 in series with theoperating magnet 306 of the indicator 30L way of the contacts III, theWiper 25I and its engaged first contact, the contact springs 301, thewinding of the magnet 306, the wiper 252 and its engaged first contact,the winding of R2I0, the

contacts I33, I24 and H4, and the resistor I25 to the negative terminalof the current source.

When thus energized themagnet-306 operates to. rotate the associateddisplay drum from its normal position to a position'when thenumeral llis displayed through the window of the indicator 30!. Incident to theoff-normal movement of this display drum,'the contact springs 308'aremoved into engagement to complete an alternative circuit for energizingthe pulse repeating relay Rfllfl and the magnet 306 in series with theoperating winding of the off-normal relay R390. This circuit extendsfrom ground by way of the operating winding of the relay R390, thecontact springs 308, the winding'of themagnet 306, the wiper 252 and itsengaged first contact, the wind-.- ing of RZIEI, the contacts I33, I24and "H4, and the resistor I20 to the negativeterminal of thecurrent'sourcej. After thiscircuit is"completed, the contact Springs 301are disengag'd toopen the This circuit extends from groundby initiallycompleted circuit energizing the relay R2I0 and the magnet 306 inseries. When energized in the above-traced circuit, the relay R390 locksup in a circuit which includes its holding winding and the contacts 39Iand 38L At its contacts 333, the relay R390 disconnects the marking lead390, which is individual to the indicator group 300, from ground. At itscontacts 302, the relay R390 completes a path including the resistor 395for impressing the negative potential of the current source upon themarking lead 304. I. The change in potential on the marking lead 394serves to mark the indicator group 300 as busy in the contact set of therotary switch 250 over which the test relay R220 is controlled in themanner explained below.

The pulse repeating relay R21 0, upon operating in response to thereoperation of the pulsing relay RI I0, closes its contacts 2I3 totransmit a ground pulse to the pen recorder III, whereby the impulse astransmitted to the indicator 30I is recorded.- At its contacts 2H and2I2, the relay R2I0 completes a circuit for energizing the operatingmagnet I06 of the ten thousands indicator IOI provided in the checkingpanel I00. This circuit extends from ground by way of the contacts 2I I,the wiper 20I and its engaged first contact, the contact springs I01,the winding of the magnet I06, the wiper 202 and its engaged firstcontact, the contacts 2I2 and the resistor 2I4 to the negative terminalof the current source. When thus energized the magnet I06'actuates theassociated display drum one step from the normal position thereofso'that the numeral 1 is displayed through the Window of the indi-'cator IOI. Incident to the off-normal movement of this drum, thecontact'springs I08 are closed to complete an'alternative circuit forenergizing the magnet I06, after which the contact springs I01 areopened to interrupt the initially completed circuit for energizing thismagnet. The indicated alternative circuit is more direct and extendsfrom ground by way of the contact springs I08, the winding of the magnetI06, the wiper 202 and its engaged first contact, the contacts 2I2, andthe resistor 2| 4 to the negative terminal of the current source.

Whenthe pulsing relay RIIO again releases during the open-circuitperiodof the second impulse, it opens the operating circuit for the digitrelay RI20, recloses the operating circuit for the digit relay RI30 and,at its contacts H4, deene'rgizes the series-connected windings of thepulse repeating relay R2 I 0 and the magnet 306. In releasing, the relayR2I0 opens its contacts2I3 'to deenergize the operating magnet of thepen recorder IT! and, at its contacts2l2, deenergizes' the magnet I06 ofthe first indicator IOI." The manner in which the second, thirdandfourth impulses are repeated by the pulsing relay'RI I0 and the pulserepeating relay R2I0 to the operating magnets 306 and I06 of theindicators 30I and IOI, and by the relay R2I0 tothe pen recorder III,will be readily apparent in view of the above explanation. At th end ofthe digit'the display drums of the two indicators IOI and 30I are eachoperated to a position wherein the numeral 4 is displayed'thereby. Inthis regard it will be noted that during the impulse repeating operationthe operating circuits for the two digit relays RI 30 and RI 20 arealternately opened and closed at the contacts I I2 and I I3 by thepulsing, relay RI I0. Due to the slow-to-release charac teristicsthereof, the two relaysRI20 and RI30 remain operated during each digitdialed at the sending station. 7 I

Shortly following the end of the first digit, the relays RIIO and RI 20sequentially restore. In releasing, the relay RI20 opens its contactsI24 to interrupt the. circuit, for energizing the pulse repeating relayR2I0 in series with the magnets of the indicators in the selected group,and closes its contacts I25 to prepare the operating circuit for thetestrelay R220. At its contacts, I23, the relay RI20 deenergizes the digitrelay RI30. At its contacts I2I, the relay RII20 completes a circuitthrough the contacts I3I for energizing the operating magnet 204 of thedigit sequence switch 200. At its contacts I22, the relay RI20 completesa circuit through the contacts I32. for energizing the operating magnet255 of the digit sequence switch 250. When thus energized, the magnet204 operates to advance the wipers 20I and 202 out of engagement withtheir associated first contacts and into engagement with theirassociated second contacts, whereby the circuit for transmitting currentpulses to the magnet I06 of the first indicator Ilfll is broken and thecircuit for energizing the operating magnet of the second indicator I02is prepared. Shortly following the release of the relay RI20, the digitrelay RI30 restores and opens its contacts I3I to deenergize the magnet204.. At its contacts I32, the relay RI30 deenergize the magnet 255. Atits contacts I36, the relay RI30 deenergizes the relay RI45. At itscontacts I34, the relay RI30 further prepares the operating circuitforthe test relay R220.' At its contacts I35, the relay RI30 prepares thecircuit for energizing the go signallamp I64.

- The magnet 255, upon releasing, advances the wipers 25I, 252,253 and254 out of engagement with their associated first contacts and intoengagement with their associated second contacts, whereby the operatingcircuit for the magnet 306 of the first indicator 30I is opened and acircuit is prepared for transmitting current pulses to the Operatingmagnet of the second indicator 302. Shortly after the wipers of theswitch 250 are stepped to engage their associated second contacts, therelay RI45 releases and closes its contacts I40 further'to prepare theoperating ciredit for the test relay R220.

The manner in which the five impulses of the second digit are repeatedto the operating magnets of the two indicators 202 and 302 and to thepen recorder'II'I, will be clearly apparent from the above explanation.It will be understood from this explanation that the three relays R5120,RI30 and RI45 are reoperated at the'b'eginning oithe second digit andremain operated until the digit is ended. It will also be understoodthat at the end of the digit the indicating drums of the two'indicatorsI 02 and 302 are operated to offnormal positions wherein'the numeral isdisplayed thereby. At the end ofthe' digit, the relays EHO, RI20, RI3iIand RI45' are sequentially released in thatorder, whereby the wipers 'ofthe two sequence switches ZIid and 250 are stepped a second step.Incident to this stepping operation,ithe pulsing" circuit controlledbythe pulse repeating jrelay R2! is transferred to include the operatingmagnet of the indicator I03,

and thepulsing circuit controlled by the pulsing indicators )3, I04-andI05 oi the checking panel I00 and to the indicators 303, 304 and 305 ofthe indicator group 300 in a manner which will be clearly apparent fromthe preceding explanation. In this regard it will be understood that atthe end of the dialing operation the code number 45678 is posted in thechecking indicator panel I00 and in the indicator group 300. This numberas interpreted by the attendant at the receiving station indicates thespecific item of information received by the operator at the sendingstation. The code number as posted in the checking panel I00 permits theoperator at the sending station to verify the code number as itistransmitted to the receiving station. In this regard it is pointed outthat if the attendant at the receiving station is in doubt as to theauthenticity of the received information, she may ask the operator atthe sending station to repeat the transmission of the code number. Tothis end, the call back key 365 is operated to complete an obviouscircuit for energizing the call back signal lamp I05. When this lamp isenergized at the sending station, the operator is informed thatverification of the transmitted code number is requested.

Incident to the transmission of the last digit of the code number, thedig t sequence and indicator selecting switch 250 is automaticallyoperated to select another group of indicators at the receiveing stationin which no code number is posted. In this regard it will be recalledfrom the preceding explanation that when the display drum of the first.indicator I in the indicator group 300 is operated to an off-normalposition, the oilnormal relay R390 associated with this indicator groupis locked energized. With this relay operated, the'negative terminal ofthe current source isconnected to the marking lead 394 to indicate thatthe indicator group 300 has a code number posted therein. On the otherhand, when no code number is posted in the indicator group 300, theoff-normal relay R390 is deenergized such that the marking lead 394 isconnected to ground through the contacts 393. In a similar manner, thefour other marking leads 200, 26L 252 and 263, individual to the fourother indicator groups,

indicator group, i. e., that individually associated above, the wipersof the switch 250 are operated to engage their respective associatedsixth contacts, and the four relays RIH), RI20, RI30 and RI aresequentially released. With the wiper 253 in this position, theoperating circuit for the testrelay R220 is further prepared. Thiscircuit is completed at the contacts I46 in response to the release ofthe relay RI45, and may be traced as extending from ground by way of thecontacts I25, I34 and I46, the winding of R220, the wiper 253 and itsengaged sixth contact, and the marking lead 200 to the negative terminalof the ,current source. It will be noted that if the Wiper 253 finds themarking .lead 260 connected to ground, indicating that the associatedindicator group is idle, the winding of the test relay R220 isshort-circuited over the circuit just traced and does not operate. Ifenergized in this circuit, the relay R220 locks up in a circuit WhlOhmcludes'the contacts HI and 223, and

the resistor 226.

energizing the magnet 255. I This magnet, in 010- crating, opens itscontacts 256 to deenergize'the stepping relay R233. In restoring, therelay R230 opens its contacts 23I 'to deenergize the magnet 255; Whenthe magnet 255 is deenergized the wipers of the switch 253 are steppedout of engagement with their associated sixth contacts and intoengagement with their associated seventh contacts. Thus the above-tracedoperating' circuit for the test relay R220 is broken at the wiper 253.The magnet 255, in releasing, also closes its contacts 256 to againenergize'the stepping relay R239. This relay, in reoperating,

closes its contacts 23I to again energize the magnet 255. Theinterrelated operation of the stepping relay R239 and the magnet 255continues until the wipers of'the switch 253 are advanced to engagetheir associated eleventh contacts, wherein the marking lead 26!,corresponding to the third group of indicators, is connected to thewiper 253 to complete a test circuit which includes the Winding of thetest relay R229. I1 this marking lead is also connected to the negativeterminal of the current source, the Winding of the test relay R220 isnot deenergized and the stepping operation of the switch 253 continues.On the other hand,,if the third group of indicators is at normal, suchthat the marking lead 26! is connected to ground, the winding of thetest relay R225! is short-circuited. When thus deenergized, the relayR22?! releases and open its contact-$222 to interrupt the operatingcircuit for the stepping relay R230 and thus prevent the lat-' .terrelay from reoperating to again energize the cult. At-its contacts 224,the relay R220 recom- I pletes the circuit for energizing the go signallamp I 64, this circuit now extending from ground by way of the wiper254 and its associated-eleventh contact, the contacts 224 and I 35, andthe filament of the lamp I34 to the negative terminal of the currentsource. Following the release of the test relay R220, the third group ofindicators is selected through the wipers of the switch 253 for use inposting the digits of the code number next dialed by the operator at thesending station.

From theiabove explanation it will be understood that shortly follcwingthe transmission of a code number to a selected group of indicators atthe receiving station, operation of the switch 250 is initiated tosearch for another group of indicators in which no code number isposted. It will also be apparent that the searching operation continuesuntil an indicator group in whi ch no code number is posted is found.Under oer:

tain'circumstancesthis may entail the opera tion of theiswitch 250 totest several groupsof indicators before an idle group "is found. Duringstarted.

If ,for any reason the operator at the sending ingthe restoring relayRIIil.

7 six indicators in the checking panel Ice.

station desires to pass the last portion of the indicators of a selectedindicator group after the first indicators of the group have been set todis-- play a code number, the indicator pass key Idii is momentarilyactuated to its off-normal position. When this key is operated'to itsoil"-normal position the contact springs I55 are closed to complete acircuit, including the resistor i5 3 and the contacts I25, I 34 and M5,for energizing .the test relay R223. The test relay, upon operating,locks up ina circuit including the contacts 22I and 223 and closes itscontacts 222 to initiate the interrelated operation of the steppingrelay R230 and the operating magnet 255 in the manner explainedabove. Asthese two circuit elements interact, the wipers of r the switch 2553 areadvanced step by step through the positions corresponding to theunoperated indicators of the selected group and into the positioncorresponding to the first indicator of the next indicator group. Ifthis next indicator group is busy the searching operation of the switch255 continues. It is only terminated when the wipers are advanced to theposition corresponding to the first indicator of the first availableindicator group in which no code number is posted. V

As indicated by the preceding explanation, the checking indicator panelIllil is provided for the purpose of enabling the operator'at thesending station to verify each code number transmitted to the receivingstation. It will be understood, therefore, thatthe'indicators of thispanel are to be isstored to normal at the end ofeach dialing oper ation.To this 'end, the restoring key Mil is momentarily actuated to itsoff-normal position immediately after a dialing operation is completedand the'posted code number is checked; Incident to this operation, thecontact springs I43 are closed to complete an obvious circuit forenergizing the release magnet 29,3. This magnet, inoperating, attractsits associated holding pawl, permitting the spring biased' wipers 2EIIand 202 to be'returned'to normal. At the contact springs I, an obviouscircuit is completed for energiz This relay, inoperating, closes itscontacts III to prepare a looking circuit for itself; At its contactsI72 to H3, inclusive, the relay'RI'Itl prepares a circuit fortransmitting restoring pulsesto the operating magnets of each of thefive indicators in the checking panel mil. At the contact springs I52ofthe key I40, a circuit is prepared or completed for energizing thewinding of the restoring relay RI8I] 'in series with the operatingmagnets of the This circuit,- when completed by the pulse generator 3II, extends from the negative terminal of the current source :by way ofthe commutating con tacts of the pulse generator 3| I, the winding of RI80, the contact springs I 32, the contacts Ill. to I16, inclusive, andthe parallel-connected windings of the six indicator operating magnetsto ground. VVhen' energized in this circuit, the relay RI closesits'contacts IBI to complete the pre} pared locking circuit for therestoring relayRI Iii. At its contacts I82, the relay Rite closes an obvious'shunt path across the contact springs I 42, thereby to prevent therestoring pulse circuit from being interrupted in response to therelease of the key' l lii. With the two relays RI'IQ and RI80 operated,restoring pulses are transmitted from the'pulse generator 3II to theoperating magnets of the five indicators 'Ii lI, I52, 33, I

and I05-until'al1'of the display drums of these 'indicatorsihave beendriven to their respective normal positions. These pulses are obviouslytransmitted through the winding of the relay RI80, which relay being ofthe slow-tb-releas'e type remains operated until the pulsing circuit isbroken. In thisregard it is pointed out that when the-indicating drum ofeach indicatoriis returned to its normal or blank position, theassociated cam is operated to break the restoring pulse circuit throughthe Winding of the associated magnet. Thus when the display drum of theindicator ml is moved to its-normal or blank position, the contactsprings 100 are disengaged to interrupt therestoring pulse circuitthrough the associated magnet I06. Also, the contact springs I01 aremoved into engagement to reprepare the circuit, controlled by the pulserepeating relay R2l0, for energizing the magnet I06. It will beunderstood, therefore, that after the display drums of the fiveindicators l fill, E02, I03, I04 and I05 have been restored to theirnormal or blank positions, no further current pulses are transmittedthrough the winding of the relay RI80. Accordingly, this relay restores.In releasing, the relay R480 opens its contacts I18! to The latter thedigits of another code number.

The attendant at the receiving station, in order to restore to normalany particular'groiupof indicators, actuates the associated indicatorrestoring key. Thus in order to clear the indicator group 300 of thecode number set up therein in the manner explained above, the restoringkey 340 is momentarily actuated to its off-normal position, wherein thecontact springs 34l and 342 are respectively operated into engagement.

At the contact springs 3 an obvious circuit is completed for energizingthe connect relay R310. At the contact springs 342, a circuit isprepared for transmitting current pulses through the winding of therestoring relay R380 and the parallel-connected windings of theoperating magnets of the indicators in the indicator group 300. Therelay R310, upon operating, closes its contacts 31] to prepare a lockingcircuit for itself. At its contacts 312 to 316, inclusive, the relayR310 completes the circuit for transmitting restoring pulses to theoperating magnets of the'indicators in the indicator group 300. Thesecurrent pulses are transmitted over a circuit which extends from thenegative terminal of the current source by way of the commutatingcontacts of the pulse gener; ator 3| I, the winding of R380, thecontactsprings 342, the contacts 31.2 to 316,inclusive, theparallel-connected magnet windings of the indicators in the group 300,and the operating winding of the relay R390 to ground. Whenenergized bythe first current pulse transmitted over this circuit, the relay R380closes its contacts 383 to complete an obvious path in shunt with thecontact springs 342 and thus prevent the restoring pulse circuit frombeing opened until all of the indicators of the group 300 have beenrestored to normal. At its contacts 38!, the relay R380 opens thelocking circuit for the off-normal relay R390. At its contacts 382, therelay R380 completes the prepared locking circuit for the connect relayR310; Each time a restoring pulse is transmitted to the operating magnetof any one of the fivev indicators in the indicator group 300, themagnet operates to advance the associated display drum one step.Accordingly, after a given number of pulses have been transmitted to themagnets of the indicators in this group, the display drums of theseindicators are restored to normal. In this regard it is again pointedout that when the display drum of any indicator is moved to its normalor blank position, the associated commutator controlled contact springsare operated to interrupt the restoring pulse circuit. For example, whenthe display drum of the indicator 30| is returned to normal the contactsprings 398 are disengaged to prevent further energization of the magnet306. Also, the contact springs 301 are moved into engagement to preparea pulsing circuit over which impulses may be transmitted to this magnetunder the control of the pulsing relay RI l0. After all of theindicators in the group 300 are restored to normal, no further circuitis available for energizing the operating winding of the oil-normalrelay R390 or the winding of the restoring relay R380. Accordingly,these two relays release in the order named, The relay R380, uponrestoring, opens its contacts 382 to deenergize the connect relay R310.Following the restoration of the latter relaythe indicator controlcircuit 3l0 individual to the indicator group 300 is fully restored tonormal. 7

While one embodiment of the invention has been disclosed, it will beunderstood that various modifications may be made therein which areWithin the true spirit and scope of the invention.

What is claimed is:

'1. An indicating system comprising a plurality of groups of individualmulti-positioned character'indicating means, means whereby eachindicating means is moved to its different positions indicating itscharacters by a series of successive impulses, the number of whichcorresponds to the character to be indicated, impulsing means :'fortransmitting series of impulses, the number in each series beingindicative of the character represented by said series, a multi-positionsequence switch having a position for each indicating means throughwhich the impulses for operating it are routed, means for advancing thesequence switch from position to position, means operated at thetermination of each series of impulses for operating the advancing meansto advance the sequence switch to the next position, and means operatedWhen the sequence switch encounters a group of indicators in which anindication is setup for operating the advancing means to move thesequence switch from position to position for said group until it movesto a position corresponding to the first indicating means of the nextgroup.

2; An indicating system comprising a plurality of groups of individualmulti-position character indicating means, means'whereby each indicatingmeans is moved to its diiTerent positions indicating its characters by aseries of successive impulses, the number of which corresponds to thecharacter to be indicated, impulsing means for transmitting series ofimpulses, the number in each series being indicative of the characterrepresented by said series, a multi-position sequence switch having aposition for each indicating means through which the impulses foroperating it are routed, means for advancing the sequence switch fromposition to position, means operated at the termination of each seriesof impulses for operating the advancing means to advance the sequenceswitch to the next position and means operated when the sequence switchencounters a group of indicators in which an indication is set up foroperating the advancing means to move the sequence switch from positionto position for said group until it moves to a position corresponding tothe first indicating means of the next group, said last means includinga test device controlled by said switch and operative to determinewhether or not an indication is posted in a group of indicators whensaid switch is operated to the setting corresponding to the firstindicator of the group.

3. An indicating system comprising a plurality of groups of individualmulti-position character indicating means, means whereby each indicatingmeans is moved to its diiferent positions indicating its characters by aseries of successive impulses, the number of which corresponds to thecharacter to be indicated, impulsing means for transmitting series ofimpulses, the number in each series being indicative of the characterrepresented by said series, a multi-position sequence switch having aposition for each indicating means through which the impulses foroperating it are routed, means for advancing the sequence switch fromposition to position, means operated at the termination of each seriesof impulses for operating the advancing means to advance tion toposition for said group until it moves to a position corresponding tothe first indicating 'means of the next group, said last means includinga test device controlled by said switch and operative to determinewhether or not an indication is posted in a group of indicators whensaid switch is operated to the setting corresponding to the firstindicator of the group and means controlled by said test device forautomatically advancing said switch through the settings correspondingto the indicators of a group in which an indication is posted.

WM. WALTER OWEN, Executor of the Estate of Bernard D. Willis, De-

ceased.

